1. Technical Field
The present invention is related generally to the field of immunochemistry. More particularly, the present invention is related to antibody heteroaggregates which cause normal cytotoxic cells to attack specifically targeted cell types.
2. State of the Art
The most widely used methods for eliminating pathogenic or otherwise undesired cells is through the use of drugs. In most cases, however, drugs are not totally specific for the target, and serious side effects result. This is especially true for anti-cancer agents which are highly toxic for normal cells and produce severe adverse reactions. Moreover many types of neoplasms are unresponsive to chemotherapy. Similarly anti-viral or immunosuppresive drugs also often exhibit many side effects.
One of the methods for obtaining increased specificity is through the use of target-specific antibodies, especially monoclonal antibodies. Such antibodies can, through their antibody binding sites, bind specifically to a designated target cell, for example a virally-infected cell, a tumor cell, a parasite, or a particular type of normal cell which expresses a distinctive cell surface antigen. However, the mere binding of antibodies to cells does not always lead to their destruction. Therefore, attempts have been made to render the antibodies cytotoxic by attaching a drug, toxin or radiolabelled isotope to them. Such "magic bullets", are under intense investigation. However, in many cases the antibody conjugates do not reach the target tissue because they are cleared rapidly from the circulation. Moreover, often large amount of antibodies must be injected and when they are taken up non-specifically by the wrong cells, serious side effects can result. Because of such limitations, a better method for destroying unwanted cells in vivo is needed.